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I I Q 16,773 Oct. 18,1927. MONTELHET I Re ELECTRIC TRANSMISSION ARRANGEMENT Original Filed May 6, 1915 gluucnloz Reiaue'd a. 1a, 1927.

,UNITED s'rATss Rs: 16,773 PATENT OFFICE.

.AN'IOHIN monrnxnn'n'r, or rams, rnnncn, assrenoza 'ro socm'rn mom-mas 'rnnnenarnns nnouann BELIN, or rams, FRANCE.

ELECTRIC TRANSMISSION ARRANGEMENT.

Original No. 1,411,866, dated April 4, 1922, Serial No. 785,920, filed Kaye, 1 918. Application relesueflled Kay 4, 1925. Serial No. 28,000.

One of the difiiculties met with in the long distance transmission of electric signals by overhead, underground and submarine lines is the capacity effect of these'lines, which capacity is sometimes very great so that continuous current in traversing them experiences a retardation which is often considerable' The object of the present invention is the employment of continuous wave alternating current of high frequency in all cases where this difliculty is met with, and particularly for the purposes of telegraphy, the transmission of.pictures, and other analogous uses, associated with an optical receiver, such as a mirror galvanometer, .or an oscillograph,

' that is to say, a receiver which works with fiel or any other galvanoscope having the deflection of a luminous beam occasioned by variations in the current traversing an arran ement placed in a suitable magnetic same efiect.

In view of the employment of alternatlng current, capacity need no longer be taken into account; it is only necessary that the signals to be transmitted should occur at a frequency less'than that of the alternation of current and that at the receiver, the optical arran ement should be of high sensltiveness in or er that there may not be any fear of trouble in connection with registering.

1 At the transmitting station the current 15 produced b an alternator working at a high and variab e frequenc and the continuous wave current thus p uced is sent either directly into the line, or into the prima' of a transformer b means of which a igh voltage is applie to the. line.

It is ointed out that this arrangement is quite dlstinct from the arrangement using pulsatory or oscillatory current for certain cases of syntonized transmissions.

The apparatus roducing the signals will be .in series with t a primary or the secondary of the transformer. ,t,

In-those cases where seriesof identical intsare to be transmitted, it is suflicient a or the speed of succession of these points to be less than the frequency of the alternating current in order that trouble ma not arise, but in certain cases it maybe esirable to send into the line a current of variable intensity, the variations being produced,: for

for

instance, bythe insertion of resistances or by modifying the resistance of a microphone.

Disturbances at the receiving apparatus should theoretically-be produced since during the return of the spot of light the re sistance may have'changed, but if the frequency is sufiiciently high, es ecially in relatlon to the movement of t e part which causes these disturbances, the symmetrical correspond to the variations produced by the transmitter,

Referring to the drawing Figure 1 is a diagrammatic view of a transmitting station employing a shunt connection.

Figure 2 is a similar view incorporating the principles of the'jWheatstone bridge.

It is obvious that the transmitter be of a kind such that its resistance is too small to exert a sufficiently strong action when connected in series with the line, a shunt connection could be used. For nstance, when the variations in the resistanceof a micro phone due to pressure exerted upon its iaphragm produced in any suitable manner are emplo ed at the transmitter the microphone wil be connected in parallel with the primary of the transformer.

By this means the diagram forming Figure 1 of the accompanying drawings is obtained. In this dia am A is the alternator, C the principa condenser, c a variable condenser for the pur uses of regulation, P, the primary, and the secondary of the transformer connected with the line. S and S are variable resistances provided for urposes of protection and of regulation.

ith this system there can be sent with a relatively small power (less than 1 kilowatt) signals or current variations produced in the line b traversing of prints, printing blocks, etc., t e transmission being eflected to considerable distances and by the employment of cables, without the necessity for taking account of capacity. By reason of the damping action the frequency should be chosen as .low as possible.

The arrangement is based on the Wheat-- stone bridge and is shown in. Fi re 2 of the drawings. The two branches rom one of the terminals A comprise respectively the microphone M and the re ulatable resistance R. The primary P o the transformer forms the diagonal of the brid e.

From the other terminal 2 start two branches, one formed of a high resistance 0,

'paratus or the regulation thereof, and also and the other b a very low resistancewhich may even be a s ort circuit a, the connections themselves forming this low resistance. It, in this arrangement, a balance has been obtained and pressure is exerted on the diaphragm of the microphone diminishing its resistance, the current will traverse the primary P in a fixed direction chang ng from one value to a higher value. The first value could correspond to balance conditions that is; to say, could be zero.

If now 6 and'c areinterchanged by a s1n1- ple change-over device, as indicated, the balance conditions will be inverted, that is to say, the maximum current would traverse the primary and this'current would diminisli when pressure was exerted on the diaphragm. With continuous current the polarity will be opposite in the two. cases, ut this feature does not exist when working with alternating current. If then in the first case the opaque end of the scale of tints corresponds to the weakest current, then the transparen will increase as the pressure on the microp one increases. In the second case the weakest current would correspond to'the transparent part and the beam would be returned towards the opaque end-of the a scale by pressing on the m1c r0phone,that is to say, the registered image would be the inverse of the first case. This results from the operation of inverting the connections of c e without touching the scale of tints or anyof the regulating devices.

Havin now particularly described and ascertaine the nature of the said invention and in what manner the same is to be performed, I declare that what I claim is:

1. .n telephotographic systems of transmission,'sending apparatus having analternating current system, a transformer in the alternating current system having one of the elements connected with the sending apparatus, a Wheatstone bridge connection 1ncluding means for enabling the inversion ofthe image without changing the sendin up including said sen ing apparatus, and a regulatmg resistance having on one side a very terchanging the two aements in the second part of the bridge the balance conditions are changed, and accordingly the direction of displacement of the luminousbeam at the receiver ischanged.

2. In facsimlle transmission, the combination with a record to be transmitted of a source of high frequency alternatim current, a transformer having rimary and secondary windings, a microp ione including means to vary its resistance according to the record to be transmitted, and circuits connecting said elements whereby a decrease in resistance of the microphone causes a decrease in current supplied to the transformer, and vice versa. 1

3. In facsimile transmission, the combination with a record to be transmitted of a source of high frequency alternting current, a transformer having primer and secondary windings, a modulating evice forsaid source operated from the the record to be transmitted, and connected in a path in shunt with the primary winding, and a connection from said source to said primary windin whereby a change in impedance of the device causes a reverse change in current supplied to the transformer. 4. In, facsimile transmission, the combination with a record to be transmitted of a source of high frequency alternating current, a transformer having primary and secondary windings, a current modulating device adapted to have its im edance varied according tothe record to e transmitted, means whereby a decrease in impedance of the de- 'vice causes a decrease in current supplied to In witness whereof I afiix n1 signature.

AN TON IN MON EILHET. 

